Funding:This work is partially funded by the BMBF contract number: 05K16VKA.The acquisition rate of commercially available line array detectors is a bottleneck for beam diagnostics at high-repetition rate machines like synchrotron lightsources or FELs with a quasi-continuous or macro-pulse operation. In order to remove this bottleneck we have developed KALYPSO, an ultra-fast linear array detector operating at a frame-rate of up to 2.7 Mfps. The KALYPSO detector mounts InGaAs or Si linear array sensors to measure radiation in the near-infrared or visible spectrum. The FPGA-based read-out card can be connected to an external data acquisition system through a high-performance PCI-Express 3.0 data-link, allowing continuous data taking and real-time data analysis. The detector is fully synchronized with the timing system of the accelerator and other diagnostic instruments. The detector is currently installed at several accelerators: ANKA, the European XFEL and TELBE. We present the detector and the results obtained with Electro-Optical Spectral Decoding (EOSD) setups.